In the year 3990, the immortal Oldna Poseidal rules Pentagona, a war-torn solar system of five planets. Daba Myroad is a survivor of the Yaman Clan, just one of numerous native societies nearly wiped out by the tyrant. Living on the remote planet Koam with his friend Mirao Kyao, Daba possesses L-Gaim, a humanoid mecha known commonly as a "Heavy Metal" and the last known relic of the Yaman Clan. The pair befriend Fanneria Amu, an aspiring actress, and Lilith Fau, the last surviving fairy in Pentagona while on the run from a band of thieves attempting to steal L-Gaim. Daba promises to fulfill the dying wish of one of the thieves hunting him—an honorable act that leads him to the powerful merchant Amandara Kamandara. With their mission in sight, the ra group will face powerful adversaries and become entangled in a rebellion against Poseidal's reign.

The adventures of a whiny teenage Miyamoto Musashi, his electro-sword and demon-sealing revolvers, and his quest to win the love of the beautiful Kaguyahime.

Childhood friends Tomo Aizawa and Junichirou "Jun" Kubota do everything together, whether it be training or just enjoying a fun day out. Anyone would think that these two are best friends for life. The only issue is that the tomboyish Tomo is in love with Jun, but he regards her like a brother. At the start of their first year of high school, Tomo confesses her feelings to Jun. However, her rough mannerisms and lack of hesitance to throw a punch do nothing to sway Jun's heart. Realizing that he will remain indifferent to her affections unless she does something about it, Tomo must find a way to knock some sense into Jun and open his eyes to what is right in front of him.

In the world of Ars, humans lead a decades-long war against giant beasts that ravage the lands and feed on their resources. Those tasked with fighting them are champions called nagimori, who utilize the destructive power of kannagi: beings gifted with uncontrollable magical powers. While mourning the death of his war partner, former nagimori Jiiro crosses paths with Kuumi, a young woman who has just awakened her magical powers. After the pair form a contract to save the city from a giant beast attack, Jiiro learns that Kuumi has escaped a laboratory and is being hunted by the underlings of Mezami, the head of the research facility. Reluctantly agreeing to help Kuumi flee from her pursuers, Jiiro starts traveling with his new partner and her friend Myaa, a young girl with a cat headdress. As the unlikely trio wanders the Arsian lands, top officials begin setting their plans into motion—and the group of adventurers soon discover that men are to be feared more than monsters.